1. Technical Field
The present invention relates to a crosshead, and more particularly to a novel improvement for forming a pair of sheets by bisecting a parison using a first dividing body of a pair of separators provided in a lower portion of a core or a die, and a second dividing body provided on the die or the core.
2. Description of the Related Art
In recent years, a plastic fuel tank for use in an automobile, for example, has been molded by forming a cut line or the like in a sheet-form resin or parison instead of a conventional cylindrical parison. In so doing, a space for mounting an insert-molded component in an interior of the tank is secured while realizing gas permeability and various functions.
A configuration described in Patent Document 1 serving as a first conventional example shown in FIG. 4, for example, may be cited as related art for obtaining a pair of sheets from a parison by forming a cut line in the parison.
In FIG. 4, a reference numeral 1 denotes an accumulator. A parison 3 discharged downward from an annular discharge port 2 formed in a lower portion of an extrusion apparatus 1 is bisected by a body 5, the body 5 being provided on a holder 4 positioned below the extrusion apparatus 1, so as to hang down via driven rolls 6 positioned on respective sides of the body 5. As a result, a pair of sheets 7 can be obtained from the parison 3.
Further, in a plastic sheet manufacturing apparatus described in Patent Document 2 serving as a second conventional example shown in FIG. 5, a parison 3 suspended from a die 8 of an extrusion apparatus 1 is cut by a cutter 5 positioned below the die 8 and then opened out into one sheet 7 via an opening member 9.
Furthermore, in a blow molding method described in Patent Document 3 serving as a third conventional example shown in FIGS. 6 and 7, a parison 3 discharged through a core 9 provided in a die 8 of an extrusion apparatus 1 is formed into a pair of divided sheets 7 by a flow passage restricting dividing member 5 of the core 9. The pair of sheets 7 hang down via driven rolls 6, and are insert-molded together with a component 22 between a pair of molds 20, 21.
Patent Document 1: Japanese Patent No. 4,295,213
Patent Document 2: Japanese Patent Application Publication No. H6-218792
Patent Document 3: Japanese Examined Patent Publication No. H4-2087